Changes in the position of male rhesus monkeys in interactional networks in a free-ranging social group will be measured by graph- theoretical sociometric techniques. Causal factors will be determined through log-linear statistical techniques. The data base consists of records of social interactions made continuously for five years on a group of monkeys at Cayo Santiago, Puerto Rico. Of special interest will be the shifts in interactional patterns occurring immediately after a sudden change in dominance rank. The study will contribute to the understanding of the interface between the individual and the social group in general, beyond increasing our understanding of the mechanisms which underlie social organization among free-ranging primates.